AB1859 CERVICAL INVOLVEMENT IN CALCIUM PYROPHOSPHATE DEPOSITION DISEASE - DISEASE SPECTRUM
Authors: E. Costa, C. Campinho Ferreira, A. M. Gomes Correia, D. Esperança Almeida, P. Pereira, J. Silva, M. Cerqueira, J. Redondo Costa, A. R. Ribeiro, J. Neves
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Calcium pyrophosphate deposition disease (CPPD) is microcrystalline arthropathy that affect space joints and fibrocartilage, leading to inflammation and structural damage. CPPD affects predominantly the appendicular skeleton. For this reason, CPPD has several pseudonyms such as pseudogout, pseudo-rheumatoid arthritis, and pseudo-osteoarthritis. The involvement of the axial skeleton is less common or recognized but may have a broad spectrum of clinical presentations. <h3>Objectives</h3> To describe the clinical spectrum of axial manifestations of CPPD. <h3>Methods</h3> Case report and discussion. <h3>Results</h3> <b>1–Asymptomatic deposition of calcium pyrophosphate (CPP) in C1-C2</b>: 68-year-old woman, diagnosed with CPPD with a pseudogout-like presentation. Previously, a knee arthrocentesis has been performed during an episode of monoarthritis. Blunt crystals with weak birefringence and positive elongation were identified in the synovial fluid analysis by polarized light microscope, compatible with CPP crystals. Later, the patient underwent a brain computed tomography (CT), after a head trauma, and it was observed the presence of calcification of the atlas transverse ligament (figure A), without associated symptoms. <b>2–Crowned Dens Syndrome</b>: A 59-year-old woman, with a definitive diagnosis of CPPD secondary to iatrogenic hypomagnesemia by proton pump inhibitor, requested urgent evaluation due to inflammatory neck pain with 2 days of evolution. She reported sudden onset during the night, limitation of cervical mobility, and fever (38.1ºC). Moreover, the patient had suspended her medication (colchicine and oral magnesium) 1 month before the onset of complaints, without medical advice. Analytically, she presented acute phase reactants elevation. Cervical spine CT showed mineralization of the transverse atlas and alar ligaments (figure B). The patient completed a low-dose corticosteroid regimen and restarted the usual medication, with rapid and complete recovery. <b>3–Retro-odontoid pseudotumor</b>: An 85-year-old woman followed by neurosurgery for clinical signs suggestive of cervical myelopathy was referred to rheumatology. From the imaging study carried out, she had CT and MRI of the cervical spine and skull, where calcification and marked thickening of the atlantoaxial ligament complex and peri odontoid soft tissues were identified, with anterior dislocation of the odontoid and stenosis of the vertebral canal at the medullary bulb transition (figure C). Clinically, she reported longstanding episodes characterized by mixed rhythm cervicalgia. She denied a previous history of peripheral arthritis. Radiographic and ultrasound studies evidenced triangular fibrocartilage of the carpus and knee menisci chondrocalcinosis, and intracartilaginous hyperechoic images in multiple locations, suggestive of CPP deposition. The patient started therapy with colchicine 1mg/day and cervical orthosis for symptomatic control. <b>4–Inflammatory discitis:</b> 78-year-old male, hospitalized for inflammatory neck pain, wrist and metacarpophalangeal joints arthritis, dysphagia, dyspnea, urinary incontinence, and fever. The laboratory analysis showed acute phase reactants elevation, without leukocytosis. After an exhaustive investigation of infectious etiology and refractoriness to multiple antibiotics, the patient started high-dose corticosteroid therapy with rapid resolution of complaints. The CT image showed C4-C5 and C5-C6 discitis with osteophytosis leading to pharyngeal anatomical distortion and periodontal and posterior longitudinal ligament calcification (figure D). <h3>Conclusion</h3> The axial involvement of CPPD can have several clinical presentations, from asymptomatic to acute presentation with manifestations of other organ systems. The imaging findings of axial involvement are distinctive and can be crucial in the diagnosis. The differential diagnosis with other etiologies in situations of acute presentations, namely infectious, is imperative. Recognition of this potential clinical manifestation is essential to avoid underdiagnosis. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.